Variable-speed mechanism.



1. H. BRlM SON. VARIABLE SPEED MECHANISM,

APPLlCATlON FILED APR.23, I915.

Patented Jan. 4, 1916.

3 SHEETS-SHEET I J. H. BRIMSON.

VARIABLE SPEED MECHANISM. APPLICATION FILED ARR. 23,1915.

Patented Jan; 4, 1916.

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E IN VENTOR.

BY I WATTCRNEY 5:: l g NW Q m\ w/ -v\ v llnNl d 7 h FIT I: v w h ,9 T L w 4 m 1. H. BRIMSQN. VARlABLE SPEED MECHANISM. APPLICATION FILED APR. 23.1915. 1,166,656, Patented Jan. 4, 1916.

3 SHEETS-SHEET 3- I7. 5 WHZVESJESI W WINE/V7012.

, M By 7771 r Arromx U TE TATES PATENT OFFICE,

JAMES BBIMSON, OF SAGINAW, MICHIGANQASSIGNOR OF ONE-HALF T WILLIAM H.

HART, OF SAGINAW, MICHIGAN.

VARIABLE-SPEED MECHANISM,

Specification of Letters Patent.

"Saginaw, in the county of Saginaw and State of Michigan, have invented certain new and useful Improvements in Variable-Speed Mechanism; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

' gears are not This invention relates to change speed gears and transmissions such as are commonly employed in the transmission of automobiles and like machines, in which a'number of speeds ahead are required and one or more speeds to reverse.

My invention applies more particularly to that class of change speed mechanisms in which the speed is changed by throwing gears of different speed ratios into and out of operation, and in which the teeth o-fthe disengaged or slid into mesh when change of speed occurs, but are thrown into and out of operation by means of sliding keys engaging the hubs of the gears, or by equivalent means.

In the type of change speed mechanism to which my present improvement is especially adapted, all the gears are rotating all of the time when the machine is in operation, so that a shift from one speed to another may be made while the gears are in motion, it

- being unnecessary to start a gear from rest 5 descending hills, but

when a shift in speed is to be made. In the type of mechanism referred to, means is provided by which change of speed from high to low may be made without shifting the clutch and with only a slight change in the speed of the engine, and all of the changes in speedare adapted to be controlled by a single lever.

My present improvement relates more particularly to a device incorporated in a change speed mechanism having the characteristics above enumerated, whereby the mechanism is better adapted for use in very hilly country where it is desirable to use'the engine as a brake, to operate as a compressor and supply braking resistance to the car while descending a steep grade.

It is common in the general type of slidegeartransmissions which are well known in the art, to utilize the engine as a brake While only in a limited way.

It is'of course evident that in descending a hill the engine is more effective 'as abrake when it is in low gear, for the reason that the momentum of the car while descending the hill is then absorbed by tending to rotate the engine at its highest speed against the resistance of its compression.

When the browof a hill is v-approafched Patented Jan. 4 1916. Application filed April 23, 1915. Serial No. 23,340,

and descent is commenced on lowl-gean'iithe slide transmission will effectively utilizeithe engine as a brake, but I i of the hill is approached on high speed, and if, with the slide transmission, it is desired to use the engine as a the hill, the engine, being still in high gear, will not be very effective as a brake, for the reason that the engine is then revolved by the momentum of the car at a much lower speed than it would be if the. engine were connected in low gear. It frequently occurs that the braking power of the engine when connected in high gear, is not enough to sulficiently check the speed of the car and with a slide gear transmission it is extremely difficult and sometimes dangerous to shift the gears during the descent of the hill from high to low speed, in order to utilize the increased brakin power of the engine at low gear. The di culty of making the shift with slide transmission from high to low while descending the hill arises from the fact that the shift of a .slide transmission necessitates, first, throwing out the clutch, then shifting the gears from high to neutral and again 'shiftingthe gears to throw the low gear into mesh. Meanwhile the momentum of thecar is revolving the gearsat brake in descending 6 5 frequently the! brow a high rate of speed and it is exceedingly diflicult to properly mesh them. Consequently gears of a slide transmission while descending a hill, in order to increase the braking power of the engine by throwing it into low speed. With my improvement, on

the other hand, I am enabled while descenditis seldom attempted to shift the ing the hill, .not only to. shift from high to low without endangering the gears, but I am also enabledto make the shift without a' longitudinal section,

a part sectional side view of a. pairof gears driving formed integral. Fig. 8, is a diagrammatic end view of the parts shown in Fig. 7

As is shown in the drawings, the device consists in a main shaft 1, counter-shaft 2,

and idler-shaft 3, upon which proper gears are mounted. At one end of the main shaftand mounted to revolve loosely thereon is a drive gear 4 having a hub 5, to which driving power may be applied in any suitable manner. Loosely mounted upon shaft 1 is a plurality of gears, each of which is capable of revolving independently of shaft 1, as on a journal. I have shown three such gears, 6being the intermediate speed gear, 7 the slow speed gear, Counter-shaft 2 carries a gear 9 that meshes with gear 4: and gear 10 that meshes with gear 6, and gear 11 meshing with gear 7, and a gear 12 that meshes with a pinion 13 carried by the idler shaft 3, which may be revolubly mounted in suitable bearings 14 carried by the gear case;24;. Gears 10 and 11 are arranged on shaft 2, so as to revolve freely on the shaft in one direction, and to be locked to the shaft when the gears are rotated in the opposite direction. Gears 9 and 12 are fixed to the shaft 2, and pinion 13 meshes with the reverse gear 8 on shaft 1.

By means of a sliding key 16 on the shaft 1, the speed ratios are changed by successive engagement of the key with the gears on that shaft, the general operation being as follows: Assuming that the engine has been the car direct-connected, that is, with the main-shaft 1 revolving at the full speed of the engine, and assuming that it is desired to change from this high speed to the lowest speed, the low speed gear is first locked to the shaft 1 by shifting key 16 until it engages the hub of gear 7, suitable jaws being provided in the hub for that purpose. Gear 7 had been previously revolving freely with relation to shaft 1, having been propelled by gears 4 and 9, shaft 2 and gear 11; aild when key 16 is shiftedso as to lock gear 7 to shaft 1, as above mentioned, gear 7 immediately picks up the speed of shaft 1, that speed being faster than the speed at which it had previously been propelled by gear 11. The speed of gear 11 is, therefore, accelerated, and it begins to turn faster than the shaft 2, upon which it is mounted. Gear 11 v gine begins pick and 8 the reverse gear.

is mounted on shaft 2 so as to turn freely on it in one direction only, as has been noted above,and it, therefore, is capable of traveling in onedirection at a faster speed than that of shaft 2. The car itself has been assumed to be traveling at a rate corresponding to high speed, and the main shaft 1 is revolving at a corresponding rate. The car, therefore, travels forward under its own momentum at high speed, while the engine continues to drive shaft 2 at a rate corresponding to slow the car has decreased until the speed of shaft 1 corresponds to the speed at which shaft 2 is being driven, gear 11 becomes locked to the shaft, and thereupon the en- In a similar manner, any other speed can be thrown in by shifting the keys while the car is traveling at high speed, without the necessity of disengaging themain'clutch of the engine, and when the keys are set for any lower speed the car will automatically up as soon as its speed has dropped to that ofshaft 2. Likewise the gears corresponding to any higher speed can be picked up from any lower speed by merely shifting the keys, and the higher speed will be picked up without jar, if. the speed of the car is first increased by using the accelerator in the usual well known manner.

The foregoing description sets forth the general construction and mode of operation of the type of transmission to which my present mvention is especially adapted, as distinguished from the well known slide transmission.

My present im rovement consists in adding means where y the connection between the engine and the drive-shaft of the car may be changed from direct-connection or high speed to low speed, without shifting the clutch, whereby when the car is about to descend a hill, the engine may be actuated by of the momentum of the car, while the car is traveling down grade.

As has already been described, gear 11 is loosely mounted on shaft 2, while gear 9 is keyed to the shaft. I provide on shaft 2 a sliding clutch which comprises a sleeve 17 having suitable jaws 18, which are adapted to engage corresponding jaws 19 formed integral with gear 11. Sleeve 17 is secured to shaft 2 by means of keys 20, along which the sleeve has a limited longitudinal movement. I will assume, for purpose of illustration, that the car is descending a hill on high speed, that is, with hub 5, which is connected to the engine, locked by means of key 16 to the main shaft 1, which is conto drive the car at slow speed.

speed. When the speed of I ,nected to the wheels of the car.

' drive the engine at The hub 5 and the shaft 1 will of course be traveling at the same speed, the momentum of the car operating the engine as a compressor and the .engine thereby serving as a brake to check acceleration of the car. If however, it is found that the braking power with the gears set for high speed, is not sufficient, the driver may shift sleeve 17 along shaft 2 until jaws 18 and 19 interlock, thereby looking gear 11 to shaft 2. Thereupon the driver Withdraws key 16 from its engagement with gear 4 and keys gear 7 to shaft 1. The momentum of the car will then drive shaft 1, gear 7, gear 11, shaft 2, gear 9-and gear 4. and the engine. ency to cause the momentum of the car to a faster ratethan before and the engine thereupon exerts an increased braking resistance to further check the speed of the car as it does down the hill. Any suitable means may be employed for shifting the sleeve 17 to engage and disengage the jaws 18 and 19, but in practice I prefer to employ the shifting device shown in Figs. 5 and 6, or its equivalent.

21 is a fork adapted to engage the sleeve 17 the fork being mounted on a slidable rod 22 carried by suitable bearings or guides 23 attached to the gear base 24. Rod 22 has a limited longitudinal movement, being actuated by one arm of the L-lever 25. push-rod-26 is preferably connected to the L-lever 25 and extends outside the gear case 24. The rod 26 preferably'projects through the foot board of the car, so that it may be moved up or down by the drivers foot, to throw clutch teeth 18 into or out of engagement with teeth 19 of gear 11.

I have shown anddescribed gears 10jand' .11 on shaft 2 as being independentof each other, but for the purpose of my present improvement these gears might be formed integral or secured together in any suitable manner. If the two gears 10 and 11 are fastened together, it is then possible, ing key 16 so as to engage gear 6, to utilizethe intermediate gears to actuate the engine while the car 1s going down hill in the same manner as has been described in explaining the action when low gear was em- Play This connection has a tendby shift-f the purposes set Having thus described my invention, what I I claim and deslre ent is:

1. In combination with a change speed mechanism comprising a main ing gear and a plurality of speed gears mounted thereon, keys for locking said gears respectively to said shaft, a counter shaft, gears carried thereby, adapted to revolve freely in one direction on said counter shaft, a slidable sleeve on said counter-shaft, and a clutch member carried by said sleeve and adapted "to engage one of the gears on said counter shaft and lock said gear poses set forth. 2. In combination witha change speed mechanism comprising a main shaft, a driving gear anda "plurality of speed gears mounted thereon, respectively to said shaft, a counter shaft,

ears carried thereby, certain of said adapted to revolve freely in one direction to secure by Letters Patcertain of said gears,

gears.

shaft, a drivto said shaft, for the purkeys for locking said gears on said-counter shaft, a slid'able sleeve on I 3. In combination with a change speed mechanism comprising a main shaft, a driving gear and a plurality of speed gears nfounted thereon, means for locking said gears respectively to said shaft, a counter shaft, gears carried thereby, certain of said gears adapted to revolve freely in one direction only on said counter shaft, a slidable sleeve on said counter shaft, and a clutch member carried by said sleeve and adapted to engage one of the gears on said shaft and lock said gear to said shaft, for

A forth.

In testimony whereof, I aflix my signature in presence of two witnesses.

. JAMESHIBRIMS ON.

Witnesses: I

NnLLm M. ANcUs,

J. V. CARPENTER.

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